The objective of the Clinical Core is to provide a well characterized patient population for the clinical studies within the Alzheimer's disease research program. In addition, the core will recruit and fully characterize the necessary controls for comparison purposes. Since the Clinical core represents a consortium effort of the clinical facilities and personnel at three diverse, separate medical centers, the Core is designed to standardize the approach for patient and control subject assessment for the clinical studies. As the key resource providing patients for study to the clinical project, the Clinical Core will recruit patients and control subjects to each of the research projects: AD Heterogeneity: Extrapyramidal Subtypes; AD Heterogeneity: Genetics and Epidemiology; and Hemorheology in Alzheimer's and Vascular Dementia. To accomplish its tasks, the Clinical core takes advantage of existing clinical facilities and supplements these facilities where necessary. Furthermore, the Clinical Core takes advantages of ongoing national efforts to unify certain portions of the Assessment Database for patients with dementia. As far as possible, the benefits of these efforts are incorporated into this Clinical Core database. Finally, the Clinical Core is organized to work in collaboration with the Data Management core and the Information and Technology Transfer Core.